Elsevier

Biochimica et Biophysica Acta

Volume 54, Issue 1, 25 November 1961, Pages 157-164
Biochimica et Biophysica Acta

The synthesis of methionine by enzymic transmethylation: VII. Existence of two separate homocysteine methylpherases on mammalian liver

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Abstract

In addition to the enzyme thetin-homocysteine methylpherase, rat and horse livers contain a second enzyme capable of catalyzing the methylation of homocysteine to form methionine. This enzyme differs from thetin-homocysteine methylpherase (a) in its substrate specificity which is much more favorable to the naturally occurring methyl donor betaine; (b) in its behavior towards calcium phosphate and alumina gels, and Sephadex G-75; (c) in its intracellular distribution; and (d) in its concentration in neonatal and regenerating rat liver.

The physiological significance of the two homocysteine methylpherases is discussed.

References (16)

  • W. Sakami et al.

    J. Biol. Chem.

    (1950)
  • J. Durell et al.

    Biochim. Biophys. Acta

    (1957)
  • W.A. Klee et al.

    Biochim. Biophys. Acta

    (1960)
  • J. Durell et al.

    Biochim. Biophys. Acta

    (1959)
  • J. Porath

    Biochim. Biophys. Acta

    (1960)
  • G.H. Hogeboom
  • H.J. Fromm et al.

    Arch. Biochem. Biophys.

    (1959)
  • L.E. Ericson

    Acta Chem. Scand.

    (1958)
There are more references available in the full text version of this article.

Cited by (17)

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Twenty-third paper in a series on enzymic mechanisms in transmethylation.

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